Model railway locomotive construction



1941- w. K. WALTHERS ETAL 3,

MODEL RAILWAY LOCOMOTIVE CONSTRUCTION Filed Nov. 29, 1939 5 Sheets-Sheet 1 Herman lizmple Nz'eier INVENTORS.

\ awzww ATTORNEY;

NOV. 25, 1941. w w s ETAL 2,263,711

MODEL RAILWAY LOCOMOTIVE CONSTRUCTION Filed Nov. 29, 1959 3 Sheets-Sheet 2 FIG. 4.

"FIG. 3.

. 4 WzZZmmKWalthers Herman Temple Nz'etez' INVENTORfiI ATTORNEY.

Nov. 25, 1941.

W. K. WALTHERS ETAL MODEL RAILWAY LOCOMOTIVE CONSTRUCTION Filed Nov. 29, 1939 3 Sheets-Sheet 3 YYz'ZZiamKWalfhers Herman Temple Meter 7 INVENTORS. BY V 6 Z a ATTORNEY.

Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE MO-DEL RAILWAY LOCOMOTIVE CONSTRUC- Application November 29, 1939, Serial :No. 306,644

'12 Claims.

This invention relates to model train construction in which standard parts are utilizedfor making up model locomotives patterned after various prototypes.

Heretofore, in the attempt to standardize on parts so as to decrease .costs .by volume productionof parts, there has been a considerable sacrifice in freedom of design and also in operating efiiciency of the locomotive The general object of the present invention is to provide a modellocomotive construction in which the design of various prototypes can be followed closely with standard parts and .at the same time locomotives of higher efficiency and pulling-power can be built.

A more specific object of the invention is to provide a "combination of standardgear drive units with standard wheel sets for mounting in sheet metal side frame members in making up locomotives of various sizes and types.

Another object is to provide an improved drive for modelsteam locomotives in which allof the drive wheels are driven directly from the motor, allowing the side rods to be mounted loosely to avoid binding.

Another object is to provide a method of quarter ing the wheels which allows the builder of the model to assemble the wheels onto the axles with ease and certainty as to proper quartering.

Another object is-to provide a simple and efficient means for obtaining various gear ratios for driving different types of locomotives and at the same time eliminating end thrust on the motor shaft.

Another object is to provide a new construction for the valve gear mounting whereby the valve gear is mounted on the cylinder block as a unit independently of the locomotive frame and super-structure.

Another object is to provide a sheet metal side frame construction for model locomotives in which bearings are assembled in holes in the members as distinguished from split bearings assembled in slots as heretofore.

Other objects will appearhereinafter from a description of the various embodiments of the invention.

In the drawings which illustrate the embodiment of the invention:

Figure 1 is a side elevation of the underframe and drive of a model locomotive with parts in section for illustrative purposes.

Fig. 2 is a top plan view of the model with parts in section.

Figs. 3 and 4 are views to illustrate the quartering of the drive wheels on opposite ends of a driving axle; Fig. 3'being a side elevation of a drive wheel and its axle looking towards the center of the axle; and Fig. 4 being a side elevation of the wheel on the opposite end of the axleshown in Fig.3 looking away from the center of the axle.

Fig. 5 is a perspective 'viewof the cylinder block and valve gear mounting.

Fig. 6 is a perspective View of the frame and its parts ready for assembly.

Fig. '7 is a section on line 1-1 of Fig. 2 through the cylinder block and pilot showing the mounting of the latter. 7

Fig. 8 is a perspective view showing the gear and shaft assembly parts.

Fig.9 is a perspective view of a complete chassis for a model locomotive of the 2-8-2 o-r Mikado type; and

Fig. 10 is a View, partly in side elevation and partly in section, of a tender and a part of a locomotive with the motor mounted in the tender.

The locomotive illustrated is of the 2-8-2 or Mikado type. It has two pilot or lead wheels I, eight drive wheels 2, and two trailing wheels 3.

The frame of the locomotive comprises two complemental sheet metal side members 4 disposed on edge in parallel spaced relation and held in position by small metal cross ties 5 comprising die cast blocks into which screws 6 pass for securing the side members to the respective ends of the ties. The side members are bent inwardly toward each other at the rear end above the trailing trucks 1 and the cross tie 5 at that point is shorter than those farther forward.

The cross ties 5 are located between wheel sets, the forward cross tie lying horizontal at the top of the frame with the lower part of the side members cut away beneath it to provide clearance for the lead truck 8. Likewise the short rear cross tie is disposed horizontally at the top of the frame and the side'm'embers at the rear end are cut away to provide clearance for the trailing truck I. The intermediate cross ties 5 are dis.-

ceiving the bearings and axles of the drive wheel assembly units it. Heretofore, where castframes were employed, the hearings were received in large vertical slots extending from one edge of the side members. Sheet metal side members were employed only in toy trains and in such cases the side member constituted the bearing for directly receiving the axles in relatively small holes.

In the construction adopted here, all bearings for the drive axles are rigidly mounted with re spect to the side frames and the axles are positively driven by gear drives from the motor. The assembly is easier and fewer side rod parts are needed than when sprung or equalized axles are used. The side rods in the present construction have no part in driving the wheels and can be fitted loosely to avoid the binding and loss of power that frequently occur in model locomotives when only a single axle is driven from the motor and the side rods are depended upon to drive the other driving wheels. Tests have shown that with a positive gear drive on all axles no loss of tractive effort is incurred by the omission of springs on the axles. The weight that is taken from some of the drivers on an uneven track is necessarily carried by the others and there may even be an increase in tractive effort due to concentration of more weight on fewer wheels.

The drive wheel assembly units l comprise the axle ll, knurled at the center to receive the large gear l2, a gear box formed in two complemental halves l3 assembled on a plane perpendicular to the axle H and held together by two horizontal screws [4 from each side, and the wheels 2 slipped onto the respective ends of the axle II and held in place by washers l5 and cap screws I6 extending into the ends of the axle II. The gear box halves [3 have formed integrally therewith lateral extensions I! fitting tightly in the holes 9 of the side members 4 and having an inner bore providing a bearing for the axle II. The worm I8 is mounted horizontally and longitudinally of the locomotive in an upper part of the gear box, above the level of the cross ties 5, and meshes with the gear l2 to drive the wheels through the axle.

The worms I8 for the several wheel assembly units constitute a rigid drive shaft by reason of the coupling of the several worm shafts of the different units together end to end. This coupling is a keyed coupling in which the opposing ends of the shafts are cut to receive a key l9 extending across the gap between them. A sleeve is slipped over the key and shafts during assembly to hold them in assembled relation. The length of the sleeve is made relative to the distance between gear boxes of different wheel assemblies so that the sleeve cannot move longitudinally suflicient to release the key 19 from either shaft end.

Where different types or sizes of locomotives are to be made, the distance between the wheel assembly units will vary and consequently the distance between corresponding gear boxes will vary. The worms I8, have shafts which extend out of the gear boxes a distance suitable for the shortest spacing of the gear boxes. Where the gear boxes are spaced farther apart the only change made is to provide longer keys l9 and longer sleeves 20. This will be necessary also where the different sizes of wheels necessitate greater spacing of the gear boxes. The wheel assembly units, with the exception of the wheel size, are completely standard for all locomotives. In the frame the cross ties 5 are standard, but the side members 4 are not,.since the latter must vary with different size wheels and different numbers of wheel units. However, the side frames, being of sheet metal, can be readily made in different sizes from the same set of tools by merely changing the guides used for punching and forming. v

The worms i8 are held against longitudinal movement by the shoulders 2| and washers 22 bearing against the ends of the gear box housing 13. The external shaft extensions of the Worms is are of smaller diameter than the inner central portion of the worms. The thrust washers take up the end thrust on the worms when rotating either forward or backward. The slight play in the worm gear allows a slight lateral movement of the gear l2 and its axle to move the wheels in or out for facilitating operation on curves.

The gear boxes preferably have a small hole 23 at the top for oiling the worm and where the boxes are assembled tight it is possible to practically run the gears in oil, thereby maintaining a longer life for the gears and drives and increasing the efficiency of the locomotive.

The worms l8, when coupled together constitute a rigid drive shaft in which there is very little, if any, play; each set of wheels being driven directly by the shaft. The rear end of the drive shaft has a spur gear 24 which meshes with the spur gear 25 on the end of the motor shaft 26 of motor 21. The motor 2! is located in the cab 28 of the locomotive on a vertical bracket 29 attached to a cross tie 5. However, where the cab is too small for the motor it is possible to locate the motor in the tender. Referring to Fig. 10, the motor 21 is mounted on a swivel plate 30 in the tender 3!. The drive from the motor to the spur gear 25 is by means of a flexible shaft 32 which may extend through a stoker housing 33.

The ratio of power for driving may be varied by changing the ratio of gears 24 and 25. The worm gear ratio is normally standard and preferably set at about 25:1. However, by changing the relative sizes of gears 24 and 25, it is possible to provide an over all gear ratio range of from 16:1 to 40:1. This range is more than ample to take care of any type of locomotive and scale speed. The use of spur gears 24 and 25 prevent any end thrust on the motor shaft and provides for a longer life for the motor. Heretofore the practice in model trains has been to use worm gears or beveled gears on the motor shaft and these resulted in considerable end thrust on the shaft.

The side rods 34 on the wheels 2 are loosely mounted so that there is no tendency to bind, since they no longer function in the drive as heretofore. The wheels 2 on one side are quartered with respect to the wheels 2 on the other side, as in large locomotives. Heretofore, the wheels were driven onto the round ends of the axles in a jig which determined the quartering and then the wheel sets were inserted in the frame.

The present invention provides a simple method of accurately quartering the wheels and of replaceably mounting them on the axles after the latter have been mounted in the frame. In constructing the present model it is necessary to assemble the gear boxes and axles and to place them in the frame, before the wheels are applied. For quartering purposes the ends of the axles have two sides flattened or machined off as shown at 35 in the drawings. The axles are assembled on the gears l2 by means of a jig to insure that in all axles there is the same relation between the teeth of the gear l2 and the flattened side of the axle. The gear boxes for the different drive units and: the worms are identical in size and form. Hence. whentheworms: t8. are assembled: in the gear boxes and each worm. is made to en.-

gagewith a correspondingtooth, on the gearfastened to each axle, the: flattened sides. of" all" axles will be held parallel when the gear boxesare assembled on theside frame in parallel rela-. tion, and the flattened. ends of all'. worm shafts are coupled together by the. key and? sleeve cou-. pling.

The wheels 2. are constructed with a central hub which has an opening complemental to the flattened end 35. of the axle. The crank pin 36 for the side rods 34 is setat a 45 angle from the radial plane which is parallel to the flat sides of the opening. Since the wheels can be slipped onto the ends. of the axle only in accordance with the position of the flattened ends 35, the crank pin on one wheel will always be inclined at an angle of 45 to the flattened side of the axle. Referring to Figs. 3 and 4., the wheel at the other end of the same axle will also have the crank pin at. a, 45 angle to the flattened part of the axle, and the angle between the two crank pins will be 90.

In assembly, the wheels '2 on one side of the locomotive are applied and the side rod 34 is secured in place. The wheels 2 on the other side are then applied and their side rod 34 secured to them. If, during this process, a mistake should be made in applying a wheel, it can readily be removed and turned 180 in its own plane and then applied to correspond to the other wheels. Quartering is accurate and cannot be made the cause of binding of the wheels by the side rods 34. The cap screws I6 hold the wheels in place but take no torque and therefore they the crank pin on the wheels in the plane of the flattened surfaces.

The engine cylinder block 3! and valve gear 38 are assembled and applied as a unit as distinguished from the priorpractice of mounting the valve gear on brackets secured to the frame or to the boiler. In this way, when a wheel or other part needs replacing, it is not necessary to take the valve gear apart to get at the wheel. The eccentric rod 39 of the valve gear is detached from the eccentric crank 4!], and the boiler and cylinder block units can be removed from the frame, the cylinder block unit 31 carrying with it all the valve gear 38. This greatly facilitates access to the parts mounted on the frame.

The cylinder block 31 is usually a casting having a central yoke 4| which rests on the forward cross tie 5 of the frame and is secured thereto by screws 42. Bosses 43 mounted on the top of the block serve to center the steam pipes from the boiler 44 to the cylinders.

Two spaced cross members 45 and 45 are secured to the block 3'! by a pair of studs 4'! passing through the cross members and threaded into the block. Spacers 48 mounted on the studs 41 serve to hold the members 45 and 46 in proper spaced relation and nuts 43 applied to the ends of the studs secure the parts together.

The yoke and hanger of the valve gear usually different for each size of locomotive and this difference is adjusted by using various lengths of spacer tubes 48, on the studs 41. valve parts; are all designed to fit the common assembly. plan and by cutting the eccentric rod; 39. to different. lengths the mechanism, can be adjusted to fit any. type of locomotive with fair. scale accuracy.

Various. lever combinations may be provided for the valve gear depending upon the type of locomotive to. be modeled, the valve gear in all. cases. being mounted. as a unit on theframe-work provided by-the cross members 45. and 46. In ad-. diti'on to. this, where third rail construction is employed, one of the. cross members may be pro-.- vided with the electrical contact strip. 58 forensgaging the third rail and picking up current. Where a third rail is. notv employed the drive. wheels are usually insulated between the rims and: axles and the cross members may be pro: vided with shoes for pressing against the rims of opposite wheels to; pick up the current.

Only two standard sizes of cylinder blocks are necessaryto cover the range of sizes and types of locomotives. Five different sizes, of wheels, ranging from 1 in diameter to 1%. are employed. The side frame members are different for each type of locomotive and size of wheels; The gear boxes are standard for all types, of locomotives and all wheel sizes.

Since different types and sizes of locomotives will have the frame at different heights from the rails, provision must be made to adjust the front pilot height. Heretofore the height of the front pilot. has. been taken. care. of by the cast frame which provides a front extension at a predetere mined height.

In the present invention a sheet metal front extension 5|: is secured to. the underside of the forward cross tie 5 and extends horizontally forward to. provide the sup-port for the pilot 52. The front extension has an upward bend 53 init to provide the required height and it is contem-l plated. that for each size of wheel a different front extension will be provided so that the pilot will always beat the right height above the rails. However, in some instances it would be possible to provide shims between the bracket and the cross tie to lower it relative to the frame of the locomotive. In this waypossibly only two or even one size of front extension bracket would be necessary. Different types of pilots may also require different height front extensions, it being necessary to keep the coupler on the pilot at the right height.

The leading wheels I are shown as two in numher and are mounted on the lead truck 8 which ispivotally secured to the underside of the cross tie 5 at the center of the latter by means of a link 54 to provide for lateral offset cn curves. A four wheel lead truck may be provided and secured in the same manner.

The trailing wheels 3' are two in number for the type of locomotive shown in the drawings and are secured to the trailing truck 7 which is piv otally secured to the underside of the center of the cross tie 5 just to the rear of the last set of drive wheels by means of a link 55 to provide for lateral offset on curves. A four wheel trailing truck may he provided and secured inthe same manner. As a rule, both the leading and trailing trucks will be standard for the respective two and four wheel types. 4

The links 54 and 55 which attach the lead and trailing trucks are short and on straight track they extend parallel to the tracks. Their forward ends are pivotally connected to the frame as described and their rear ends are pivotally connected to the respective trucks. Means are preferably provided for limiting the pivotal movement of the links relative to the frame. This construction avoids the necessity of a slot connection and allows the trucks to turn on curves independently of the locomotive.

In assembling the locomotive the drive gear sets and axles are first assembled without the drive wheels. The cross ties are secured to one of the side frame members. The gear boxes are then assembled on the other side frame and coupled together. Then the former side frame member with the cross ties is applied and secured to the other side frame member. The wheels are then applied and the motor and cylinder block units attached. After securing the pilot and leading and trailing trucks. the superstructure, including the cab and boil-er are applied and various detail elements secured in place to complete the locomotive model.

The method of assembly can be varied to suit the ideas of the builder. The assembly is easy to accomplish and does not require unusual skill or the use of machine tools for fitting or finishing the parts. Any number of drive Wheel units may be employed to correspond to the prototype being modeled.

The construction generally outlined above is different from the methods heretofore emp oyed in model locomotive construction and simpler and easier to follow. It employs a maximum number of standard parts, making for greater volume of production and less cost to the builder. It makes repair and replacement of parts easier and less costly.

The invention may have various embodiments within the scope of the accompanying claims.

The invention is hereby claimed as follows:

1. In model railway locomotive construction a plurality of like worm gear drive units, one for each set of drive wheels, a gear box housing for each unit comprising two complemental side members each provided With a central bearing for the axle and having suitable recesses for the gears, with the worm extending horizontally therein and in a direction longitudinally of the locomotive, and sheet metal side frame members disposed on either side of the drive units and having openings for receiving the axle bearings and holding the drive units in place.

2. In model railway locomotive construction, a plurality of like interchangeable worm gear drive units, one for each set of drive wheels, and each having a worm shaft extending longitudinally of the locomotive in alignment with the other similar shafts and disposed intermediate the wheels, means for coupling said worm shafts together end to end for simultaneous rotation, and means for driving said worm shafts to drive each of the sets of wheels directly therefrom, the driven gear of each unit being mounted directly upon an axle for a set of wheels, and each unit being housed in a gear box having side extensions providing bearings for the axle and extending directly to the respective side frame members of the locomotive.

3. In model railway locomotive construction, in combination, a plurality of like standard drive wheel assemblies including individual worm gear drive units of like gear ratio disposed intermediate the drive wheels with gear boxes formed of two halves secured together and providing bearings for the axles of the respective wheel sets,

two spaced side frame members having holes to receive said bearings and hold the gear boxes in place, means coupling the worm shafts for the drive units together end to end to extends as a substantially rigid drive shaft longitudinally of the locomotive, a motor, and a spur gear train connecting the motor shaft to said worm drive shaft at the rear of the locomotive to eliminate end thrust on the motor shaft.

4. In model railway locomotive construction, a sheet metal frame having spaced side members and a plurality of cross ties rigidly secured together, a cylinder block mounted on said frame and having means for supporting the boiler superstructure, and a rearwardly extending support removably secured to the cylinder block for supporting the valve gear mechanism.

5. In model railway locomotive construction, a sheet metal frame having spaced side members and a plurality of cross ties rigidly secured together, a cylinder block mounted on said frame and having means for supporting the boiler superstructure, and a rearwardly extending support removably secured to the cylinder block and having two spaced cross members for supporting the valve gear mechanism.

6. In model railway locomotive construction, a cylinder block having means for supporting the boiler, a pair of studs threaded into said cylinder block and extending rearwardly therefrom to hold a pair of spaced cross members, sleeves on said studs for spacing said cross members apart and from the cylinder block, and valve gear mechanism supported by said block and cross members as a unit for assembly in the locomotive.

7. In model railway locomotive construction, a frame comprising sheet metal side members held in spaced parallel relation by a series of flat cross ties and screws passing through the side members and into the ends of the cross ties to secure the same together, the central cross ties being disposed vertically, and the end cross ties being disposed horizontally to provide a rigid structure in both directions.

8. In model railway locomotive construction, a frame having a horizontal cross tie at its forward end, a cylinder block mounted directly on said cross tie, a sheet metal pilot support removably secured to said cross tie and extending forwardly at a predetermined level above the level of the rails, and a pilot secured to said support.

9. In model locomotive construction, a frame comprising sheet metal side members secured to the ends of cross ties, one of said cross ties being disposed at the forward end of the cab, a sheet metal motor bracket secured to said cross tie and extending above the level thereof, and a main drive shaft mounted on said bracket and extending through the same, said shaft having a spur gear adjacent the bracket for driving the locomotive.

10. In model locomotive construction, a locomotive having individual worm gear drives for the several sets of drive wheels with the worms in the different gear drives arranged substantially in the same straight line and connected to be rotated in synchronism, a spur gear train for driving said worm gears, a motor mounted in the tender of the locomotive, and a flexible shaft extending from the motor to said spur gear train to drive the latter.

11. In model locomotive construction, a locomotive having individual worm gear drives for the several sets of drive wheels with the worms in the different gear drives arranged substantially in the same straight line and connected to be rotated in synchronism, a spur gear train for driving said worm gears, a motor mounted in the tender of the locomotive on a vertical pivot, and a flexible shaft extending from the motor to said spur gear train to drive the latter.

12. In a model railway locomotive construction, a pair of side frame members with a series of cross ties securing the same in spaced relation, a plurality of interchangeable sets of drive wheel assemblies having individual worm gear drive units disposed between the side frame members, a cylinder block secured at the forward end of the side frame members, and having means for supporting the boiler, a pair of studs threaded into said cylinder block and extending rearwardly therefrom to hold a pair of spaced cross members, sleeves on said studs for spacing said cross members apart and from the cylinder block, valve gear mechanism supported by said block and cross members as a unit for assembly in the locomotive, means for driving the individual worm gear units in synchronism to drive the several sets of wheels separately, and connecting rods extending from the cylinders and valve gear mechanism and loosely connected to cranks on the Wheels.

WILLIAM K. WALTHERS.

HERMAN TEMPLE NIETER. 

